To meet the demand of future development, mobile communication systems must support high-speed grouped data transmission at a data rate as high as tens to thousands of millions bits per second. In the increasingly difficult situation of managing radio resources, it is a key research objective of the new generation mobile communication standards 3GPP LTE-Advanced (3rd Generation Partnership Project Long Term Evolution) to employ multi-input and multi-output (MIMO) wireless transmission techniques, to fully exploit and utilize space resources, and to maximize spectrum utilization and power efficiency.
In recent years, the research on the multi-subscriber MIMO wireless transmission technique has received extensive attention both in theory circles and in industrial circles. Owing to the asymmetry between uplink and downlink, multi-subscriber MIMO channels are classified into uplink multi-access channels (MAC) and downlink broadcast channels (BC). The research work is carried out in these two classifications, with focus set on the downlink broadcast channels (BC). The research on the multi-subscriber MIMO wireless transmission technique mainly centers on the scenarios in which the transient/short-time channel status information in the base station is known. Most research performed is only applicable to the scenarios of fixed and low-speed mobile communication, however some research is performed on multi-subscriber MIMO wireless transmission in middle-speed and high-speed mobile communication environments. In addition, only multi-subscriber MIMO uplink MAC transmission is considered in the research, while few reports are seen regarding the research on multi-subscriber MIMO wireless transmission methods that utilize long-time statistical channel status information. SDMA transmission that utilizes transient/short-time channel status information is not only unfit for middle-speed and high-speed mobile communication environments, but also involves complex resource scheduling at the control layer, complex implementation of the physical layer, higher cost of channel information acquisition and exchange, and higher inter-subscriber interference, and therefore it is hard to effectively improve the spectrum utilization, power utilization, and transmission reliability of the wireless communication system. For this purpose, the present invention provides a multi-subscriber SDMA technique that utilizes long-time statistical channel status information.